Engenharia Mecânica
URI permanente desta comunidadehttps://repositorio.fei.edu.br/handle/FEI/23
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37 resultados
Resultados da Pesquisa
Artigo 0 Citação(ões) na Scopus Silício: Abundante, eclético, sofisticado(2004-01-04) PAPALEO, R.Artigo de evento 0 Citação(ões) na Scopus Incremental root locus and pid tuning(2006-10-04) GOMES, S. C. P.; Fabrizio Leonardi; DA CRUZ, J. J.This work discusses the Incremental Root Locus property and one application of it to PID controllers tuning. It is shown that using that property it is easy do determine the departure angle from the real axis, which is a not a trivial task using the classical root locus rules. As an application, a procedure for tuning PID controllers in two steps is shown. Firstly it is necessary to perform a step response test using a proportional controller in order to stabilize the system. In a second step the PID design is performed by a zero-pole canceling. The controller obtained is a two-degree-of-freedom PID controller. Simulations carried out indicate that the controller associated with the setpoint tracking exhibits an almost first-order response whereas the one associated with the disturbance rejection exhibits a more oscillatory response. As illustrations, a real application for a position servo control system and some design projects tested by simulation were done.Artigo de evento 0 Citação(ões) na Scopus Another argument to consider the reliability of the uncertainty Type B similar to Type A(2006-09-22) BULBA, E. A.; SVOLL, V. R.The ISO-GUM express that the standard deviation of the experimental standard deviation of the mean q obtained for ratio σ[s(q)]/ σ (q) has a not negligible value for practical values of n, and therefore that Type A evaluations of the standard uncertainty are not necessarily more reliable than Type B evaluations. Although this correct comparison either, the assertion based on the value of the s(q) is the not best, in way that this work to consider other relation as argument for this comparison.Artigo de evento 0 Citação(ões) na Scopus Charge-based continuous equations for the transconductance and output conductance of graded-channel SOl MOSFET's(2007-01-05) Michelly De Souza; Marcelo Antonio PavanelloThis paper presents charge-based continuous equations for the transconductance and output conductance of submicrometer Graded-Channel (GC) Silicon-On-Insulator (SOI) nMOSFET. The effects of carrier velocity saturation, channel length modulation and drain-induced barrier lowering were taken into account in the proposed equations. Experimental results were used to test the validity of the equations by comparing not only the transconductance and the output conductance, but also the Early voltage and the open-loop voltage gain, showing a good agreement in a wide range of bias.Artigo de evento 0 Citação(ões) na Scopus Exergy analysis of the human respiration under physical activity(2009-08-30) Cyro Albuquerque; PELLEGRINI, L. F.; FERREIRA, M. S.; YANAGIHARA, J. I.; OLIVEIRA, S. DE.© 2009 by ABCM.This paper presents an exergy analysis of the human body under physical activity. A model of the respiratory system and a model of the thermal system were used for this purpose. They consider heat and mass transfers in lungs, tissues and blood. Each component of those models is represented by an uniform compartment governed by equations for diffusion, convection, O2 consumption, CO2/heat generation and heat and mass transfer with the environment. The models allow the calculation of the exergy destruction in the lung and tissues, and the participation of each entropy generation mechanism in the total generation. Furthermore, a discussion is proposed regarding the efficiency of the human body under physical exercise.Artigo de evento 1 Citação(ões) na Scopus Integrated manufacturing laboratory and software tools applied to an industrial engineering undergraduate course(2009-03-23) Fabio Lima; PRADO, A. C.; Alexandre Augusto Massote; Fabrizio LeonardiThis paper describes the experience of using software tools associated with an integrated manufacturing laboratory in an industrial engineering undergraduate course at FEI (Fundacao Educacional Inaciana, Brazil). The integrated manufacturing laboratory has got three complete manufacturing cells integrated by computer. The aim of the laboratory is to provide to the industrial engineering student a powerful analysis capability of how to use these kinds of systems to improve product quality and production performance. To do that, computational models are implemented using software tools like Visual Object Net++, Promodel® and WEB support. Finally, the models are validated in laboratory experiments. It was observed that such strategy has been given excellent learning results.Artigo de evento 1 Citação(ões) na Scopus Modeling heat transfer in human arm and forearm: Effect of countercurrent heat exchange and superficial veins(2009-06-25) FERREIRA, M. S.; YANAGIHARA, J. I.- Phenomenological model of particulate matter emission from direct injection diesel engines(2005-07-05) ARGACHOY, C.; PIMENTA, A. P.A new phenomenological model is introduced by applying established conceptual models for direct injection combustion to develop a mathematical description of events. The model has the capability to predict particulate mass output, as well as a particulate mass history over a single combustion event. The model was developed in a Matlab-Simulink environment to promote modularity. Results of particulate mass output from single cylinder laboratory engine, and six-cylinder vehicular engine were used to determine the validity of the predictions made. Although predicted values do not perfectly match measured values, there is certainly reasonable agreement. Copyright © 2005 by ABCM.
- A low-cost anthropometric walking robot for reproducing gait lab data(2008-12-05) Da Silva Santana R.E.; De Toledo Fleury A.; Menegaldo L.L.Human gait analysis is one of the resources that may be used in the study and treatment of pathologies of the locomotive system. This paper deals with the modelling and control aspects of the design, construction and testing of a biped walking robot conceived to, in limited extents, reproduce the human gait. Robot dimensions have been chosen in order to guarantee anthropomorphic proportions and then to help health professionals in gait studies. The robot has been assembled with low-cost components and can reproduce, in an assisted way, real-gait patterns generated from data previously acquired in gait laboratories. Part of the simulated and experimental results are addressed to demonstrate the ability of the biped robot in reproducing normal and pathological human gait.
- Removing Eddy-Current probe wobble noise from steam generator tubes testing using Wavelet Transform(2008-09-05) Lopez L. A. N. M.; Ting D.K.S.; Upadhyaya B.R.One of the most important nondestructive evaluation (NDE) applied to steam generator tubes inspection is the electromagnetic Eddy-Current testing (ECT). The signals generated in this NDE, in general, contain many noises which make difficult the interpretation and analysis of ECT signals. One of the noises present in the signals is the probe wobble noise, which is caused by the existing slack between the probe and the tube walls. In this work, Wavelet Transform (WT) is used in the probe wobble de-noising. WT is a relatively recent mathematical tool, which allows local analysis of non-stationary signals such as ECT signals. This is a great advantage of WT when compared with other analysis tools such as Fourier Transform. However, using WT involves wavelets and coefficients' selection as well as choosing the number of decomposition level needed. This work presents a probe wobble de-noising method when used in conjunction with the traditional ECT evaluation. Comparative results using several WT applied to Eddy-Current signals are presented in a reliable way, in other words, without loss of inherent defect information. A stainless steel tube, with two artificial defects generated by electro-erosion, was inspected by a ZETEC MIZ-17ET ECT equipment. The signals were de-noised through several different WT and the results are presented. The method offers good results and is a promising method because it allows for the removal of Eddy-Current signals' probe wobble effect without loss of essential signal information. © 2007 Elsevier Ltd. All rights reserved.